Amber Heard and Johnny Depp at the London Film Festival on October 11, 2015.

The stars' volatile relationship, and previously unreleased testimony from their 2016 divorce, is expected to be central to Depp's defamation lawsuit against U.K. tabloid The Sun.

On Aug. 13, 2016, Amber Heard was being grilled by Blair Berk, a top Hollywood attorney employed by her now ex-husband Johnny Depp, in a Century City law office. "Johnny and I refer to his other personality, the part of him that is present when he beats me up — we call that the monster and have called [that] the monster for many years," Heard recounted during a deposition taken amid the divorce. She added, "I was petrified of the monster."

That 471-page deposition transcript is part of a trove of previously unreleased documents obtained by The Hollywood Reporter along with statements from Heard's close friend Raquel Pennington and the Los Angeles Police Department officers who responded after an altercation between the then-married couple at an L.A. penthouse on May 21, 2016. Heard's friend Tillett Wright, with whom she had been on the phone before it was allegedly thrown at Heard, had called 911.

The testimony sheds new light on the relationship and will be a point of contention in a court battle in the United Kingdom. The tabloid The Sun is defending itself in a defamation lawsuit filed by Depp over an April 2018 story headlined "How can J.K. Rowling be 'genuinely happy' casting wife-beater Johnny Depp in the new Fantastic Beasts film?" The article referenced Aquaman star Heard's application for a restraining order against the actor, which centers on that May 2016 night, and said the actress "recounted a detailed history of domestic abuse incidents, some of which had led to her fearing for her life."

The stars have painted conflicting portraits in the press of abuse in their relationship — even sparking an arbitration proceeding over an allegation that Depp defamed Heard and violated the nondisclosure agreement that was negotiated during their divorce. The actor publicly denied abusing Heard in multiple interviews last fall, and his lawyer Adam Waldman told THR in October that Depp's legal team has evidence that Heard "severely injured" Depp and "faked" abuse allegations. All of which, Heard claims, is false and defamatory.

Heard's account of the events leading up to the split, along with those of other witnesses, will be scrutinized as The Sun defends its story. Heard has asked to testify in the U.K. proceeding, but a source with knowledge of the matter says Depp's legal team has refused to allow it and even threatened to sue her for violating their NDA if she does. That's why Heard's previous divorce testimony could become key, although Depp's camp insists she'll be allowed to testify if The Sun calls her.

There are high stakes in the case, and a different set of legal standards than Hollywood stars are typically used to. In the U.S., the person suing for defamation must prove the statement concerning him or her was false, but in the U.K. the allegedly defamatory statement is generally presumed false unless the defendant can prove it was true. For that reason, testimony about the alleged abuse will play prominently in Depp's U.K. case — where it is up to The Sun to disprove Depp's claims of what happened that night.

In the deposition transcripts obtained by THR, Heard claimed that on May 21, 2016, at the L.A. residence, Depp threw her phone at her "as hard as he could" and it hit her in the face. She claims he then grabbed her by the hair and she screamed for help. She stated that he "broke a lot of glass things that left glass on the floor," and the ground was covered in damaged objects including silver candlesticks and a lamp, among other items.

That's when, according to the deposition, Heard's friend Raquel Pennington arrived at the penthouse. Pennington testified that she'd been in an adjacent apartment and came over after Heard sent a text asking her to. When she arrived, she heard Depp yelling. Pennington said Heard asked for help and told her Depp had hit her with the phone. She said Depp was "swinging around" a magnum bottle of wine and knocking things off the counter with it. Pennington testified that Depp's yelling eventually prompted his security team to enter, and one of the guards convinced him to leave. She also said that she had taken "dozens of photos" of Heard's bruises during the course of their friendship, including on that night.

The LAPD officers who responded to the 911 call that night also were deposed as part of the divorce proceeding. Officer Melissa Saenz, in a July 18, 2016, deposition, testified that Heard refused to give her name, so she didn't realize who the famous actress was until weeks later. Saenz said Heard was crying but she did not see any marks, bruises, swelling or signs of injury on her face. The officer also testified that she inspected the apartment and saw no signs of shattered glass or broken items. Saenz said Heard repeatedly "shook her head" in response to questions and did not want to talk, and that she had no probable cause to believe a crime had been committed. Officer Tyler Hadden shared similar testimony.

Heard testified that she declined to give a statement to the officers at the advice of her lawyer. Meanwhile, Pennington said the officers saw "all of the damage," including the broken glass, and offered to "go arrest him right now" if Heard filed a report. LAPD officers Saenz and Hadden denied in their depositions ever saying that.

Berk, the lawyer who questioned Heard on behalf of Depp, asked her whether she had ever struck, slapped or thrown an object at the actor. Heard said she "did her best" to defend herself against her bigger, stronger husband.

Depp recounted a different set of events leading up to that evening. The actor, in a July 2018 filing in The Sun defamation lawsuit, claimed Heard was "aggressive and violent" and punched him in the face twice the night of April 21, 2016, after he was late to her birthday dinner. The night of May 21, he said he went to the penthouse to retrieve some of his belongings and brought two of his security guards with him because he "was concerned about what Ms. Heard might do."

Depp said he tossed the phone on the sofa and it didn't hit Heard, nor did he touch her. He claimed Heard started yelling at him after he walked across the room and that's when his security guards came in and she started crying. He also claimed the damage in any photos taken by Pennington that show smashed items in the penthouse and Heard's injured face were not caused by him, and that "hardcopy photographs were put in evidence, but neither the original images nor the associated metadata were produced."

While the depositions may play a role in the U.K. court proceedings, the relationship is also being reexamined as the stars' conflicting accounts continue to make headlines two years after their split.

Depp took his claims public, at length, in a British GQ feature published on Oct. 2 with a cover line teased as, "The divorce. The violence. The excess. The vengeance." In response, Heard's reps called Depp's framing of the issue "outrageous" and characterized it as "psychological abuse." Depp's team fired back, teasing evidence to be submitted in the U.K. suit that would show "Ms. Heard repeatedly violently attacked and severely injured Mr. Depp, and then faked abuse allegations against him."

As part of their divorce, the stars agreed not to discuss their marriage or make derogatory statements about each other. In an arbitration demand, Heard claims Depp violated that agreement and defamed her in several media outlets this fall by giving the impression that she falsely claimed to have been physically abused. The actress argues the statements, including ones made by Waldman on Depp's behalf to THR, were made with malice and she's entitled to punitive damages.

Recently, Heard penned a Washington Post op-ed, titled "I spoke up against sexual violence — and faced our culture's wrath. That has to change." Although Depp's name isn't mentioned, the piece was widely interpreted as being about him. The actress wrote that she "became a public figure representing domestic abuse" and "felt the full force of our culture's wrath for women who speak out." Heard says she was told she'd be blacklisted, a global fashion brand dropped her as its celebrity face and it was unclear whether her Justice League and Aquaman roles would remain hers. In response, Depp's lawyer Waldman stated that Heard's column was an "abuse of the #metoo movement" and claimed she "masquerades as victim rather than abuser."

A hearing in the U.K. matter is currently set for Feb. 22, and Waldman says Depp's team will introduce evidence including multiple depositions, photographs and eyewitness statements.

In response to Waldman's statements, and Depp's claims in the U.K. filings, Heard's lawyer Eric George tells THR, "Mr. Depp's ongoing defamation and violation of the parties' confidentiality agreement is already the subject of a pending arbitration. We won't dignify his comments with any further response."

Waldman, meanwhile, claims Heard withdrew her arbitration complaint and suggests that if she "would like to go to court ... we will see her there."